Pollen morphology in Dodartia, Lancea, Leucocarpus, and Mazus and an analysis of pollen morphotypes in the Mimuleae (Scrophulariaceae)

1984 ◽  
Vol 62 (6) ◽  
pp. 1287-1297 ◽  
Author(s):  
Charles L. Argue

The pollen grains of Dodartia, Lancea, Leucocarpus, and Mazus are single, radially symmetrical, isopolar, and suboblate to prolate with trizoniaperturate ectocolpi; the colpus membranes show various patterns of transverse rupturing but most frequently have a single, equatorial rupture. The exine is composed of a semitectate sexine 2, a simplicolumellate sexine 1, and a frequently foveolate to perforate nexine, thinner than the sexine. Data from the present and earlier studies on the Mimuleae are analyzed statistically to establish a specific set of correlated morphological characters with discriminatory value in the definition and delimitation of major pollen types for the tribe. Interspecific and intergeneric palynological variation among tricolporate Mimuleae is assessed and taxonomic implications of the pollen data are discussed.

Phytotaxa ◽  
2021 ◽  
Vol 497 (2) ◽  
pp. 79-96
Author(s):  
ANDRÉA ONOFRE DE ARAUJO ◽  
MAURO PEIXOTO ◽  
CINTIA NEVES DE SOUZA ◽  
EDUARDO CUSTÓDIO GASPARINO ◽  
JULIANA TOLEDO FARIA ◽  
...  

A natural hybrid between Goyazia and Mandirola (Gloxiniinae, Gesneriaceae) from Cerrado (Brazil) is here described, supported by pollen morphology, cytological data and morphological characters. The microsporogenesis of Mandirola hirsuta and that of the hybrid were analyzed in order to evaluate the cytogenetic characteristics. The haploid chromosome numbers observed were n = 12 for M. hirsuta and n = 11, 13, 16 and 26 for the hybrid. Structural abnormalities (monads, dyads, triads and micronuclei) were observed at the final of the hybrid’s meiosis. High viability rates of the pollen were recorded for Goyazia and Mandirola (>90%) and low viability for the hybrid (34.7%). The pollen grains were acetolyzed, measured and photographed for pollen morphology analysis. Quantitative pollen data were analyzed through descriptive and multivariate statistics. The hybrid has intermediate pollen characteristics between G. petraea and M. hirsuta; it is more related to G. petraea by the measures of diameters and ectoapertures; it is more similar to M. hirsuta mainly regarding the microreticulum on the mesocolpium region. The hybrid and Mandirola share vegetative and flower size, while the colors of the hybrid are similar to Goyazia. Pollen morphology, cytological data and morphological characters brought clear evidence for the recognition of the intergeneric hybrid, which we named as Goydirola x punctata.


Phytotaxa ◽  
2018 ◽  
Vol 350 (2) ◽  
pp. 187
Author(s):  
DASMILIÁ CRUZ ◽  
YOANNIS DOMÍNGUEZ ◽  
CRISTINA M. PANFET VALDÉS ◽  
VITOR F. O. MIRANDA ◽  
EDUARDO CUSTÓDIO GASPARINO

We present here pollen morphology of 12 native taxa of Lentibulariaceae from Western Cuba with the aim of surveying pollen traits useful for species identification. Pollen grains were studied using light microscopy and scanning electron microscopy to search for new characteristics to contribute to the taxonomy of Lentibulariaceae from western Cuba with the aim of increasing our understanding of pollen morphology. Pollen grains were acetolysed, measured, photographed, and described based on qualitative characteristics. Here we present statistical analyses and multivariate statistics for quantitative data. The pollen grains are medium-sized, isopolar, subprolate to prolate, circular, subcircular to quadrangular amb, zonaperturate, 3-colporate, 4(5)-colporate, (6–)7–18-colporate or porate, lalongate or lolongate endoaperture, or endocingulate in some species. They may also be psilate, psilate-perforate, microreticulate to rugulate exine, and sexine thicker than nexine. Endoaperture with fastigia was reported for Pinguicula ser. Albidae and Lentibulariaceae for the first time in this study. The Utricularia species studied were grouped into three pollen types on the basis of aperture and endoaperture characteristics and shape. Morphological variations observed showed intergeneric pollen diversity in Lentibulariaceae, corroborating the taxonomic importance of such characteristics at a family level.


1986 ◽  
Vol 64 (12) ◽  
pp. 3113-3126 ◽  
Author(s):  
Barry G. Warner ◽  
C. C. Chinnappa

The pollen of 61 of about 80 taxa of Ericales that occur in Canada are described through the use of light and scanning electron microscopy. Five main pollen types are recognized: (I) compact tetrads in which the individual grains are not clearly delimited when rolled and viewed in all positions, and possessing costae endopori or costae endocolpi, (II) tetrads in which the individual grains are clearly and consistently delimited, occasionally possessing costae endopori or costae endocolpi, (III) a category in which grains within the tetrad are not consistently delimited, and lack costae endopori or costae endocolpi, (IV) loose tetrads in which individual grains are poorly fused, and (V) monads. A key identifies general morphological distinctions among the pollen groups or species. This survey of the pollen morphology of the Ericales supports conventional taxonomic treatments. We favour treatment of Monotropaceae and Pyrolaceae as separate families and suggest the elevation of Orthila secunda to its own monotypic family. The Clethraceae and Orthila secunda may be better treated outside the Ericales. We propose that the tetrad pollen of most Ericales is a derived condition from the more primitive trizonocolporate monad of the Cyrillaceae, Clethraceae, and Orthila secunda. Subfamily Vaccinioideae (Ericaceae) and Empetraceae, through subfamily Rhododendroideae (Ericaceae), to Pyrola and Moneses (Pyrolaceae), and finally to Chimaphila (Pyrolaceae) represent the evolutionary progression based on a trend from compact tetrads to loose individual grains within the tetrad. Finally the most advanced group is represented by the zonoaperturate monads of the Monotropaceae. This evolutionary progression based on pollen morphology is in accord with general principles of tetrad formation during microsporogenesis and with evolutionary relationships suggested by the macromorphology, phytochemistry, embryology, and degree of dependence on a fungal symbiont.


2014 ◽  
Vol 67 (3-4) ◽  
pp. 275-285 ◽  
Author(s):  
Dorota Wrońska-Pilarek

This paper presents results of studies on pollen morphology of 6 Polish species of the genus Ribes L. (family Grossulariaceae). Observations were carried out with LM and SEM. Pollen diagnoses were illustrated by series of microphotographs. Grains of examined species are small to medium-sized and prolate spheroidal or subprolate in shape, rarely prolate. They represent three pollen classes: zonocolporate, pantoaperturate and pantoporate. Three types of ectoapertures have been observed: colpi, pori and colpoids. Endoapertures are pori, in number (4-) 6-7-8 (-14) per grain. Ornamentation is psilate or fossulate, with the exception of the ectoaperture areas, which are granulate. According to the author, the polarity or apolarity, type of pollen class and ectoaperture, number of endopori and ratio of exine thickness to grain diameter are the main diagnostic features of the pollen grains of the native species of Ribes. The key to Polish species, basing on the morphological characters of grains is given too.


2021 ◽  
Vol 9 (10) ◽  
pp. 1386-1393
Author(s):  
Jayshree Sandesh Thaware ◽  

Pollen is appropriately referred by some as Golden dust extremely valuable on account of their tremendous applications in science, industries and public health. No other plant part even though extremely tiny in size is packed with so much information and power. Similar to other plant parts, pollen characters are so varied that the classification system of plants can be built up entirely on the basis of pollen morphology.Palynology is the distinct branch of biology that deals with the dispersed microscopic tiny living and fossil entities including pollen grains, spores, algal and fungal fragments and others. An important aspect of Palynology is the Pollen morphology. The importance of Palynology in taxonomic and phylogenetic consideration of plants is well known. The changes occurring through hybridization and years of cultivation are reflected in pollen morphology. The scope and interest in the study of pollen morphology have widened with the advent of Scanning Electron Microscopy (SEM) and with regards to unipalynous taxa particularly the understanding of finer morphology is of fundamental importance. SEM gives a correct understanding of exine surface as the electron photographs of the surface replica of the exine provides the exact picture of the ornamentation pattern. The variation in the pollen morphological characters helps in the classification of plant taxa and their assessment of their phylogenetic relationship. In the present investigation, the pollen morphological studies were carried out of some ethnomedicinal plants like Catharanthus roseus, Allamanda cathartica, Datura metel, Brassica juncea, Raphanus sativus and Cleome viscosa pollen grains by Scanning electron microscopy. All that they possess anticancer characteristics in common.


Bothalia ◽  
1983 ◽  
Vol 14 (3/4) ◽  
pp. 849-856 ◽  
Author(s):  
M. L. Frean

Pollen grains of the Euphorbiaceae show a number of pollen types which can be clearly distinguished. Generally different genera are characterized by a specific pollen type.  Euphorbia obesa Hook. f. and Croton gratissimus Burch, subsp.  subgratissimus (Prain) Burtt Davy, represent two genera within the Crotonoideae with different morphology, each type characteristic for the respective genus. Taxonomically, the genus Euphorbia with apetalous flowers consisting of a naked pistil surrounded by several staminate flowers within a cyathium, is considered more advanced than the genus  Croton. In  Croton the inflorescence is a raceme with unisexual flowers. The floral whorls of the male show numerous anthers and both calyx and a showy corolla are present. Both genera are insect pollinated. In both  Euphorbia obesa and  Croton gratissimus the pollen wall in section shows columellae, a structure characteristic of angiosperms. However the present ontogenetic studies show that the formation of the columellae differs entirely in the two pollen types. The final stratification of the wall as well as the morphology of the grains differ and evaluation of the exine structure indicates that phylogenetically Croton pollen shows more advanced characters than  Euphorbia — contradicting the floral phylogeny. This study conducted at light and electron microscope level compares the two pollen types morphologically and ontogenetically, concentrating mainly on the formation of the exine which is tectate-perforate in the prolate tricolpate grain of Euphorbia obesa and semi-tectate in the anaperturate, spheroidal grain of Croton gratissimus. The aim of the study was to evaluate the significance of pollen characters in taxonomic and phylogenetic relationships within the Euphorbiaceae. The differing pollen morphology which is related to the taxonomic grouping of tribes within the subfamily (Crotonoideae) emphasizes diversity, which may result from physiological adaptation. The study shows that the same functional end may well be achieved in different ways and this may be a factor underlying the diversity in the heterogeneous family Euphorbiaceae.


Phytotaxa ◽  
2013 ◽  
Vol 139 (1) ◽  
pp. 39 ◽  
Author(s):  
YU-LAN PENG ◽  
XIN-FEN GAO ◽  
LU PENG

The pollen morphology of 15 species representing four sections of Youngia and 11 species from six other genera of the tribe Cichorieae was investigated. Measurements and observations were conducted through scanning electron microscopy. This study aims to provide new and useful information regarding the extent of pollen morphological diversity within the genus Youngia and related genera in the tribe Cichorieae and thus to contribute to a better understanding of the taxonomy and evolution of these groups. Six pollen types, distinguished primarily by the number of apertures and spines in the polar region, are described. Palynological characters are not useful for the delimitation of Youngia and its closely related genera Crepidiastrum, Ixeridium, and Crepis at the generic level, and did not fully resolve the relationships between the groups. The distinction of Faberia from the other members of the subtribe Crepidinae is supported by the pollen characters. Pollen morphology also did not support that Youngia sect. Desiphylum sensu Babcock and Stebbins may be separated at the generic level either as Tibetoseris or Pseudoyoungia. Four pollen types were found in Youngia s.l., i.e. Y. racemifera type, Y. japonica type, Y. prattii type and Y. sericea type, which partly reflect the sectional classification of Youngia sensu Babcock and Stebbins. The systematic position of Y. racemifera should be reconsidered according to pollen characters. The pollen data suggest that Y. sect. Mesomeris is not monophyletic, and the relationships of its species require further examination.


2019 ◽  
Vol 6 (2) ◽  
pp. 98-105
Author(s):  
Andreia Santos do Nascimento ◽  
Carlos Alfredo Lopes de Carvalho

This study aimed to characterize species of Myrtaceae belonging to genera already identified in the pollen spectrum of beehive products of social bees, describing pollen grains morphology and correlating with taxonomic differences the species reported in the literature. For each plant species, measurements were made with 25 pollen grains in equatorial view and the polar diameter (PD) and equatorial diameter (ED) were measured. The exine thickness was obtained by measuring 10 pollen grains in polar view at the medium height of mesocolpium. The description of pollen morphology showed that pollen grains of the species are triangular amb, 3-colporates, psilate surface, small to medium size and oblate shape with the P/E ratio ranging from 0.52 to 0.72 µm. The morphological description of Myrtaceae species showed similarity between several characteristics common to pollen grains of this species. The description also allowed separation of nine species studied by size and specific morphological characters with the identification key, which can also be used to study the pollen spectrum of hive products.


2016 ◽  
Vol 46 (3) ◽  
pp. 333-336
Author(s):  
Alexsandro ZIDKO ◽  
Luiz Antônio RODRIGUES ◽  
Cláudia Barbieri Ferreira MENDONÇA ◽  
Maria Lucia ABSY ◽  
Marcos Gonçalves FERREIRA ◽  
...  

Abstract The crabwood (Carapa) represents an important source of natural resources. The objective of this work was to study the pollen morphology of the three species of Carapa (Meliaceae) registered in the Brazilian Amazon. The pollen grains were obtained from floral buds, pistillate and staminate flowers of Carapa guianensis, C. surinamensis and C. vasquezii. In order to explore the taxonomic implications of the pollen study for these species of Carapa, lactic acetolysis method was used for light microscopy study. Furthermore, the non-acetolyzed material was used in the study of the scanning electron microscopy. It was found that the three Carapa species present little variations in pollen morphology. Compared to the other species this study, Carapa vasquezii has higher values for the length and width of endoaperture; however, it has lower values for polar and equatorial diameter, equatorial diameter in polar view and apocolpium side.


Author(s):  
Kadry Abdel khalik ◽  
Suad Al- Ruzayza ◽  
Abdullah Assiri ◽  
Ahmed Elkordy

Pollen morphology of 20 species belong to seven genera (Abutilon, Althaea, Hibiscus, Malva, Pavonia, Senra and Sida) of Malvaceae from Saudi Arabia were studied by using light microscope (LM) and scanning electron microscope (SEM). Quantitative and qualitative pollen morphological characters which vary among investigated taxa are found in the pollen polarity, symmetry, size, shape, polar axis, equatorial diameter, P/E ratio, average height and width of spine, aperature character and spine index. The pollen grains vary from spheroidal, prolate spheroidal, oblate spheroidal to suboblate. All taxa were characterized by relatively large to medium sized pollen grains, numerous pores scattered irregularly all over the grain, and echinate sculpturing. Sida ovata is the largest size pollen grain (138.95) µm. On the other hand, Malva parviflora showed the smallest pollen size (52.28 µm). The average height and width of spine varied greatly among studied taxa. The highest spines (20.65µm) found in Sida ovata, while the shortest (3.19 µm) was found in Abutilon pannosum. Results of the pollen shape, size, and exine sculpture characters offered useful data for evaluating the taxonomy of Malvaceae both on subgeneric and sectional levels. A key for the identification of the investigated taxa based on pollen grains characters is also provided


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